A reciprocating cutting tool comprises a motor housing; a gear box connected with the motor housing; a motor disposed in the motor housing and a reciprocating mechanism disposed in the gear box. The reciprocating mechanism comprises a suspending rack and a reciprocating shaft driven by the motor. the reciprocating shaft is connected to the motor by a reduction gear and an eccentric shaft. The suspending rack comprises a top plate and a bottom plate; the reciprocating shaft movably connected to the bottom plate, and would not beyond the top plate in a reciprocating direction. Due to the reciprocating shaft is not guided and restricted by the top plate of the suspending rack, the reciprocating shaft would not beyond the top plate during the reciprocating motion. It decreases the height of the gear box greatly, and then the height of the reciprocating cutting tool is decreased. It increases the application ability.